Expandable tubular thread protection

ABSTRACT

Herein disclosed is a method of protecting a tubular or a component attached to the tubular, comprising making two sections of the expandable tubular into two complete centralizing rings or two partial centralizing rings having a larger outer diameter than the remainder of the expandable tubular, wherein the two complete centralizing rings or partial centralizing rings are on two ends of the component. Also discussed herein is an assembly comprising an expandable tubular, a component attached to the tubular, a sleeve over the component and an adhesive; wherein the adhesive fully covers the space between the inside diameter of the sleeve and the outside diameter of the component. The sleeve remains in place when the tubular is placed down hole. Related methods and assemblies are discussed in further details.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit under 35 U.S.C. §119(e) of U.S.Provisional Patent Application No. 61/982,734, filed Apr. 22, 2014, thedisclosure of which is hereby incorporated herein by reference.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable.

BACKGROUND

1. Field of the Inventions

The present invention generally relates to protection of expandabletubular threads. More particularly, the present invention describes anexpandable tubular with at least one centralizer as an integral part ofthe tubular, said centralizer protecting the expandable tubular threads.Furthermore, this invention relates to a downhole tubular or downholeassembly, e.g., for use in an oil/gas well or a water well.

2. Background of the Invention

In recent years, the use of expandable tubulars has become more commonin the drilling and completion phases of well bore construction. Inthese phases, it is necessary to protect tubulars and related devicesfrom scarring. For example, it is necessary to protect threadedconnectors from scarring, when they are being placed in a well. It isalso necessary to protect box threads during handling and storage.

Very often, the wall of the threaded box thread is very thin. This iscaused by the minimum wall thickness to apply the thread. This threadoutside diameter (OD) is easy to ding, scar or bend out of shape. If thebox OD is scarred, the material will split while being expanded andcause a failure. The scars can be caused by the pipe rubbing the casing,casing connections, and other attachments while it is let down hole. Thescarring also occurs with a directional change. An opening is often putin the casing to put the tubular through. These openings are rough andmay have sharp and jagged edges, which will scar the tubular. In suchcases, the tubular can split with excessive scarring, which results in avery expensive repair and lost time.

A current method to prevent such damages is to attach a steel protectionsleeve by applying adhesive on the box OD with an epoxy glue applicator,as illustrated in FIG. 1. Another method may be to use a brush or paddlestick. The sleeve is then slid over the box thread. When putting on thesleeve, the glue at times is pushed off by the sleeve. When the gluesets, there is no guarantee that the glue is in contact with the sleeveand box OD. There is also no guarantee that the glue is not thicker onone side or the other since there is no control to make sure that theglue covers the entire contact area evenly.

With the sleeve is installed in this manner, several undesirablesituations can occur. (1) The sleeve touches the casing caused by thepressure of the tubing and seal. (2) The sleeve touches the casing whilestacking the tubing or casing. (3) The sleeve hits the casingconnectors. When any of the above three situations occurs, happens, theprotective sleeve can break loose. If this happens, then the sleeve mayrun up the casing or tubing. Sometimes, several of these sleeves maybecome loose and come together, which will cause problem during tubularexpansion. More seriously, there is no more protection for the threads.The threads can scar and split days later when expanded, causingextensive damage, incurring repair cost and lost time.

Accordingly, there is continuing need and interest to develop methodsand systems to protect expandable tubular threads.

SUMMARY

Herein disclosed is a method of protecting a tubular or a componentattached to the tubular, comprising making two sections of theexpandable tubular into two complete centralizing rings or two partialcentralizing rings having a larger outer diameter than the remainder ofthe expandable tubular, wherein the two complete centralizing rings orpartial centralizing rings are on two ends of the component.

In some embodiments, the component includes a box thread. In someembodiments, the outer diameter of the two complete or partialcentralizing rings is larger than or equal to the outer diameter of thecomponent attached to the tubular. In some embodiments, the tubularcomprises a casing, a liner, a screen, or a production tubing.

In some embodiments, the method furthering comprises placing a sleevebetween the two complete or partial centralizing rings and over thecomponent. In some embodiments, the sleeve is a steel sleeve. In someembodiments, the sleeve is held in place by the two complete or partialcentralizing rings to protect the component.

Also disclosed herein is an assembly comprising an expandable tubularand a component attached to the tubular; two sections of the expandabletubular having a larger outer diameter than the remainder of theexpandable tubular, forming two complete centralizing rings or twopartial centralizing rings, wherein the two complete centralizing ringsor partial centralizing rings are on two ends of the component.

In some embodiments, the outer diameter of the two complete or partialcentralizing rings is larger than or equal to the outer diameter of thecomponent attached to the tubular. In some embodiments, the componentincludes a box thread.

In some embodiments, the assembly further comprises a sleeve placedbetween the two complete or partial centralizing rings and over thecomponent. In some embodiments, the sleeve is held in place by the twocomplete or partial centralizing rings to protect the component.

Further discussed is a method of protecting a component attached to anexpandable tubular, comprising placing a sleeve over the component,wherein the sleeve comprises an input port and at least two tell holes;applying an adhesive through the input port to fill the space betweenthe inside diameter of the sleeve and the outside diameter of thecomponent until the adhesive comes out of the at least two tell holes.The adhesive fully covers the space between the inside diameter of thesleeve and the outside diameter of the component such that the sleeveremains in place when the tubular is placed down hole.

In some embodiments, the method further comprises making two sections ofthe expandable tubular into two complete centralizing rings or twopartial centralizing rings having a larger outer diameter than theremainder of the expandable tubular, wherein the two completecentralizing rings or partial centralizing rings are on two ends of thecomponent and sleeve.

In some embodiments, applying the adhesive comprises using a pump, amixing tube, and a sealed input cap. In some embodiments, the pumpincludes a plural component pump.

Also discussed herein is an assembly comprising an expandable tubular, acomponent attached to the tubular, a sleeve over the component and anadhesive; wherein the adhesive fully covers the space between the insidediameter of the sleeve and the outside diameter of the component. Thesleeve remains in place when the tubular is placed down hole.

In some embodiments, the assembly further comprises two sections of theexpandable tubular having a larger outer diameter than the remainder ofthe expandable tubular, forming two complete centralizing rings or twopartial centralizing rings, wherein the two complete centralizing ringsor partial centralizing rings are on two ends of the component andsleeve.

The present invention comprises a combination of features and advantageswhich enable it to overcome various problems of prior devices. Thevarious characteristics described above, as well as other features, willbe readily apparent to those skilled in the art upon reading thefollowing detailed description of the preferred embodiments of theinvention, and by referring to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more detailed description of the preferred embodiment of thepresent invention, reference will now be made to the accompanyingdrawings, wherein:

FIG. 1 illustrates an existing method for protecting expandable tubularthreads. The glue is applied on areas of the box OD and the sleeve isslid on.

FIG. 2 illustrates a method of protecting expandable tubular threadswith two expandable centralizing rings (centralizers), according anembodiment of this disclosure.

FIG. 3 illustrates a method of protecting expandable tubular threadswith two expandable centralizing rings (centralizers) and an extendedsteel sleeve, according an embodiment of this disclosure. The rings holdthe sleeve in place, the sleeve cannot break loose. Adhesive is notrequired in this embodiment.

FIG. 4 illustrates a method of protecting expandable tubular threads byfilling the area between the inside diameter (ID) of the steel sleeveand the outside diameter (OD) of the threaded box completely withadhesive, according an embodiment of this disclosure. Such full coverageof adhesive stops the sleeve from coming loose and causing damage to thetubing and well.

FIG. 5 illustrates how a centralizing ring of this disclosure is madefor an expandable tubular, according an embodiment of this disclosure.

DETAILED DESCRIPTION Overview

To protect expandable tubular threads and to centralize an expandabletubular, at least a section of the tubular is enlarged to have a largerOD than the remainder of the expandable tubular, forming at least onecomplete centralizing ring or at least one partial centralizing ring(i.e., a complete ring of 360 degrees or a segment/segments thereof as apartial ring). When the tubular is being placed downhole, thecentralizing rings (complete and/or partial) serve to centralize thetubular whiling minimizing scarring and protecting the threads anddevices attached to the tubular (e.g., seals and anchors). After thetubular is placed downhole and radially expanded, the centralizing ringwill expand along with the remainder of the tubular and the expandedtubular will have the same diameter. In other words, these centralizingrings (complete and/or partial) function to centralize the expandabletubular and protect expandable tubular threads; and then they disappearafter the tubular is expanded.

As used herein, the term “tubular” refers to any tubular parts orcomponents, especially related to the oil/gas/water well applicationsand downhole processes. Examples of such tubulars include a casing, aliner, a screen, or a production tubing.

As illustrated in FIG. 2, a method of protecting expandable tubularthreads with two expandable centralizing rings (centralizers) is shown.In an embodiment, two centralizers are placed on the two ends of thethread so that when the tubular is let down hole, one centralizer isabove the thread and the other is below. These centralizers keep thethread OD from being scarred while the tubular is being placed into awell/hole. The casing connectors and casing wall cannot touch the threadOD.

Another method is illustrated in FIG. 3, wherein the thread is protectedby using two centralizers and an extended steel sleeve. In anembodiment, the centralizers are placed in the same was as the previousmethod shown in FIG. 2 and the extended steel sleeve is placed betweenthe two centralizers and cover the thread. The centralizers hold thesleeve in place so that the sleeve cannot break loose. An adhesive toattaching the steel sleeve is not required. In some cases, the extendedsteel sleeve is longer than the typical steel sleeve used in the art.The steel sleeve is long enough to cover the thread area and the spacebetween the centralizing rings. This steel sleeve is placed on the boxOD before screwing the male and female together. The expandedcentralizing rings stop the protection sleeve from moving away from thethreaded box OD when the tubular is placed down hole.

In another embodiment, as shown in FIG. 4, a method of protecting thethread using a steel sleeve is shown. The method comprises placing asleeve over the component, wherein said sleeve comprises an input portand at least two tell holes; applying an adhesive through the input portto fill the space between the inside diameter of the sleeve and theoutside diameter of the component until the adhesive comes out of the atleast two tell holes.

The adhesive to attach the steel sleeve is applied such that the steelsleeve cannot move away or become detached. In an embodiment, theadhesive is applied using a plural component pump, a mixing tube, and asealed input cap. With the sleeve in place (placed over the box OD), thesealed cap is attached to the steel sleeve. The input cap is attached toa chemical (adhesive) mixing tube. The plural components are blendedtogether as they are pumped from the unmixed adhesive containers. Thepumping continues until the adhesive comes out the small “tell holes” inthe bottom of the sleeve. The tell holes cam be in any position and whenadhesive comes out both holes, the space between the sleeve and the boxOD is completely filled. This method of applying the adhesive ensuresthat the area between the inside diameter of the steel sleeve and theoutside diameter of the threaded box is completely filled and coveredwith adhesive. This full coverage prevents the sleeve from coming looseand causing damage to the tubing and/or well. This method may be used toapply the adhesive to short sleeves or long (extended) sleeves betweenthe centralizing rings (centralizers).

The adhesive applied in this method is another layer of protection toensure that the box OD is not scarred. Because sometimes when thetubular passes through an opening in the casing, it could touch the edgeof the hole. When this happens, the tubing will ride up the approachangle of the rings/centralizers and down the other side so that thecasing wall may contact the protecting steel sleeve that is held inplace by the centralizers. With the adhesive holding the steel sleeve inplace, the box OD will not be scarred because the steel sleeve cannot bedislodged.

As is clear to one skilled in the art, the method of applying theadhesive without the centralizers is also a significant improvement overthe existing method. Furthermore, the methods discussed hereinabove arenot limited to protecting threads only but any device or attachmentrelated to a tubular that is to be placed down hole.

Advantages.

The methods discussed hereinabove reduce the possibility of damagedthreads. A damaged thread will cost many hours of down time. If thereare no replacements available, the items will have to come from thefactory and the down time would be even longer.

Using the extended/longer steel sleeve stops typical normal damages tothe threaded connection. Using the extended/longer sleeve and twocentralizers increases production and reduces delivery time. The sleeveis applied at the well. If the parts are short enough for shipment, theproduct can be made ready before delivery.

Using the disclosed method of applying the adhesive to the sleeves helpsto ensure they remain in place. Using these methods will also reduce thecost of expandable tubular products.

Method of Making Expandable Tubulars with Centralizing Rings.

In an embodiment, a centralizing ring of this disclosure is made usinghydraulic or mechanical fixtures. For example, as shown in FIG. 5, anexpanding anvil is placed in an expandable tubular (tubing or casing),at a first desired position. A sizing block (or sizing cap or sizingclamp) is attached to the outside of the tubular to insure the properdiameter of a centralizing ring is created. The anvil is thenmechanically expanded until the sizing clamp stops the expansion. Theanvil (or ram) is moved to another location and the process is repeatedto create a second centralizing ring as needed/desired. In some cases,the expandable tubular is heated before the centralizing rings arecreated. In some cases, induction heating is used to heat the tubularbefore the centralizing rings are made. Other suitable methods may alsobe used for form the centralizing rings/centralizers.

While preferred embodiments of this invention have been shown anddescribed, modifications thereof can be made by one skilled in the artwithout departing from the spirit or teaching of this invention. Theembodiments described herein are exemplary only and are not limiting.Many variations and modifications of the system and apparatus arepossible and are within the scope of the invention. Accordingly, thescope of protection is not limited to the embodiments described herein,but is only limited by the claims which follow, the scope of which shallinclude all equivalents of the subject matter of the claims.

What is claimed is:
 1. A method of protecting a tubular or a componentattached to the tubular, comprising making two sections of theexpandable tubular into two complete centralizing rings or two partialcentralizing rings having a larger outer diameter than the remainder ofthe expandable tubular, wherein said two complete centralizing rings orpartial centralizing rings are on two ends of said component.
 2. Themethod of claim 1, wherein the component includes a box thread.
 3. Themethod of claim 1, wherein the outer diameter of the two complete orpartial centralizing rings is larger than or equal to the outer diameterof the component attached to the tubular.
 4. The method of claim 1,wherein said tubular comprises a casing, a liner, a screen, or aproduction tubing.
 5. The method of claim 1 furthering comprisingplacing a sleeve between the two complete or partial centralizing ringsand over the component.
 6. The method of claim 5 wherein the sleeve is asteel sleeve.
 7. The method of claim 5 wherein the sleeve is held inplace by the two complete or partial centralizing rings to protect thecomponent.
 8. An assembly comprising an expandable tubular and acomponent attached to the tubular; two sections of the expandabletubular having a larger outer diameter than the remainder of theexpandable tubular, forming two complete centralizing rings or twopartial centralizing rings, wherein said two complete centralizing ringsor partial centralizing rings are on two ends of said component.
 9. Theassembly of claim 8 wherein the outer diameter of the two complete orpartial centralizing rings is larger than or equal to the outer diameterof the component attached to the tubular.
 10. The assembly of claim 8wherein the component includes a box thread.
 11. The assembly of claim 8further comprising a sleeve placed between the two complete or partialcentralizing rings and over the component.
 12. The assembly of claim 11wherein the sleeve is held in place by the two complete or partialcentralizing rings to protect the component.
 13. A method of protectinga component attached to an expandable tubular, comprising placing asleeve over the component, wherein said sleeve comprises an input portand at least two tell holes; applying an adhesive through the input portto fill the space between the inside diameter of the sleeve and theoutside diameter of the component until the adhesive comes out of the atleast two tell holes.
 14. The method of claim 13 wherein the adhesivefully covers the space between the inside diameter of the sleeve and theoutside diameter of the component such that the sleeve remains in placewhen the tubular is placed down hole.
 15. The method of claim 13 furthercomprising making two sections of the expandable tubular into twocomplete centralizing rings or two partial centralizing rings having alarger outer diameter than the remainder of the expandable tubular,wherein said two complete centralizing rings or partial centralizingrings are on two ends of said component and sleeve.
 16. The method ofclaim 13 wherein applying the adhesive comprises using a pump, a mixingtube, and a sealed input cap.
 17. The method of claim 16 wherein saidpump includes a plural component pump.
 18. An assembly comprising anexpandable tubular, a component attached to the tubular, a sleeve overthe component and an adhesive; wherein said adhesive fully covers thespace between the inside diameter of the sleeve and the outside diameterof the component.
 19. The assembly of claim 18 wherein the sleeveremains in place when the tubular is placed down hole.
 20. The assemblyof claim 18 further comprising two sections of the expandable tubularhaving a larger outer diameter than the remainder of the expandabletubular, forming two complete centralizing rings or two partialcentralizing rings, wherein said two complete centralizing rings orpartial centralizing rings are on two ends of said component and sleeve.